1. Field of the Invention
The present invention relates generally to the spreading of adhesive materials, and more specifically to a tool for spreading a layer of adhesive over a surface, such as a floor.
2. Description of the Prior Art
Numerous types of flooring are attached to the underlying subfloor or concrete slab using an adhesive material. The adhesive must be spread evenly over the underlying surface prior to placement of the floor. For example carpets, individual tiles, and roll out flooring material are applied over an adhesive. In addition, many roofing materials can be applied over similar adhesive layers.
The adhesives used for these purposes are typically quite viscous and sticky. They are typically spread by use of a hand trowel. The person spreading the adhesive typically works on their knees, so that application is physically very difficult, and quite slow. At the present time, application of adhesives to large areas is labor intensive, resulting in a relatively high cost of application.
Attempts have been made in the past to improve the tools used to apply the adhesive. These improvements are typically directed to spreaders which allow their use from a standing position. Examples of such tools include U.S. Pat. No. 3,803,662, issued to Glejf, and U.S. Pat. No. 4,982,470, issued to Szabo. Various other designs are also known. Particular units allow the spread of adhesive over the surface by pushing, pulling or moving them back and forth laterally.
All of the units presently available on the market suffer from various drawbacks. Some devices are complex, with various adjustable parts. The adhesive which is used tends to work its way into various small openings, making these devices very difficult to clean. Other devices are extremely awkward to use, or simply are of such a design that they are impossible to use quickly. The spreaders generally available on the market require a steady downward pressure to be applied in order to form a thin layer of adhesive. Such an application technique tends to quickly tire the person spreading the adhesive, and makes it difficult to obtain an even layer of adhesive over a large surface.
With the currently available spreaders, it is very difficult to obtain a thin, even layer of material over a large surface. The problem is exacerbated by the fact that different adhesives have different viscosities, which require more or less downward pressure on the part of the operator. This downward pressure must be applied consistently over the entire course of spreading the adhesive. Because it is difficult to obtain a good spread of adhesive with the currently available spreading tools, many professionals simply revert to using a hand trowel, and spread adhesive over floor surfaces from a kneeling position. In other words, the presently available designs do not adequately solve the problems faced by those in the business of spreading adhesives over a large surface.
It would be desirable to provide a spreader which is easy to use from a standing position. It would be desirable for such a spreader to be simple to manufacture and use, inexpensive, and easy to clean. A superior design would allow thin, even coatings of adhesive to be applied very quickly, and it would be further desirable for such a spreader to be easily adaptable to use with different viscosities of adhesive.